Apparatus for tubular drill string making or breaking

ABSTRACT

An apparatus for tubular drill string making or breaking including top wrench assembly, bottom wrench assembly, support structure, and control device. The top wrench assembly includes two top wrench bracket assemblies, top pair of movable gripping arms, top arm actuator, and top wrench camming actuator. The arm actuator allows the gripping arms to be closed or opened around the outer circumference of the pipe section, allowing top wrench assembly to engage differing casing sizes. The bottom wrench assembly includes two bottom wrench bracket assemblies, bottom pair of movable gripping arms, and bottom arm actuator. The bottom arm actuator allows the gripping arms to be closed or opened. The top wrench assembly is directly mounted on top of the bottom wrench assembly to allow relative rotation of the drill pipe section therewith. Once a pair of rollers is rotated by a hydraulic motor in the top wrench, or a pair of stationary rollers in the bottom wrench are both engaging with outer surface of the drilling string, the rollers automatically and naturally centralize or align a die insert to the most desirable central position. At this point the maximum number of die insert teeth evenly bite into the outer surface of the drill string.

FIELD OF THE INVENTION

The invention is an automated apparatus having a wrenching device integrated with a rotating device. The apparatus is used here for making and breaking tubular drill string.

SUMMARY AND ADVANTAGES OF THE INVENTION

This invention includes three major components of a top wrench, a bottom wrench, and a support structure. The top wrench can advantageously rotate clockwise or counter clockwise about the centerline of the drill string while being supported on the bottom wrench by a hydraulic actuator.

The top wrench has a clamping wrench assembly and a rotating assembly integrated into a single unit through a common structural frame or bracket. The top wrench assembly includes a wrench clamping actuator, a die insert holder and die insert, mounted at a geometrically symmetrical center between a pair of rotatable rollers through a common structural frame or bracket. The integrated top unit is pivotally mounted to the front end of an arm which is also pivotally mounted at the rear end of the arm. The top pair of arms carrying the unit can open or close at the front end while pivoting about the rear end through a hydraulic cylinder connecting both arms to engage the surface of a pipe section.

The bottom wrench has a clamping wrench assembly and a pair of stationary rollers integrated into a single unit through a common structural frame or bracket. The bottom clamping wrench assembly includes a wrench clamping actuator, a die insert holder and die insert, mounted at a geometrically symmetrical center between the pair of stationary rollers through a common structural frame or bracket. The integrated bottom unit is pivotally mounted to the front end of an arm which is also pivotally. The bottom pair of arms can open or close at the front end while pivoting about the rear end through a hydraulic cylinder connecting both arms through a pin to engage the outer surface of the drill pipe section.

Advantageously, once the pair of rollers is rotated by a hydraulic motor in the top wrench, or the pair of stationary rollers in the bottom wrench are both engaging with outer surface of the drilling string, the rollers automatically and naturally centralize or align the die insert to the most desirable central position. At this point the maximum number of die insert's teeth evenly bite into the outer surface of the drill string. This is desirable for producing an optimum and maximum making or breaking torque once the wrench clamping actuator pushes the die holder out to position the die insert against the pipe section.

The apparatus according to the invention permits usage with a range of pipe sized without having to change parts.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred exemplary embodiments of the present invention are described in further detail below in conjunction with the accompanying drawings. In which:

FIG. 1 is a perspective view of the apparatus according to the invention;

FIG. 2A is a schematic view of the top wrench assembly according to the invention;

FIG. 2B is plan view of the top wrench assembly shown in FIG. 2A;

FIG. 3A is a schematic view of the bottom wrench assembly according to the invention;

FIG. 2B is plan view of the bottom wrench assembly shown in FIG. 3A;

FIG. 4A is a perspective view of the top and bottom wrench assemblies together;

FIG. 4B is a side view of the top and bottom assemblies shown in FIG. 4A;

FIG. 5A shows a perspective view of the top wrench bracket assembly;

FIG. 5B shows a plan view of the top wrench bracket assembly shown in FIG. 5A; and

FIG. 6 shows a perspective view of the bottom wrench bracket assembly;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, the apparatus 1 for tubular drill string making or breaking according to the invention is shown. The apparatus 1 includes a top wrench assembly 10, a bottom wrench assembly 20, a support structure 30, and a control device 40.

The top wrench assembly 10 is described in greater detail with reference now to FIGS. 2A and 2B. The top wrench assembly 10 includes two top wrench bracket assemblies 12, a top pair of movable gripping arms 14, a top arm actuator 16, and a top wrench camming actuator 18. It can been seen that the top wrench assemblies 12 are mounted at an open end of each top arm 14 and are shown in contact with a section of drill pipe 2. Details of the top wrench bracket assembly 12 will be described hereinafter in greater detail. The movable arms 14 are mounted to an arm bracket 13 at a closed end of the movable arms 14 and are pivotable with respect to the arm bracket by means of pivot mounting pins 15. The gripping arms 14 pivotally connected either jointly with a single pin for both arms or in the preferred embodiment shown, with each arm 14 having the pivot pin 15 pivotally connecting each movable gripping arm 14 to the arm bracket 13. The top arm actuator 16 is pivotably linked to each arm 14 by arm actuator pivot pins 17. The arm actuator 16 allows the gripping arms 14 to be closed or opened around the outer circumference of the pipe section 2, in order for top wrench assembly 10 to engage differing casing sizes. The arm actuator 16 is preferably a hydraulic cylinder of a known type recognized in the field, therefore detailed explanation of such an actuator is unnecessary, although it will be understood other types of linear actuator may be employed. The top wrench camming actuator 18 is attached on one end to the arm bracket 13 at pin 19.

The bottom wrench assembly 20 is described in greater detail with reference now to FIGS. 3A and 3B. The bottom wrench assembly 20 includes two bottom wrench bracket assemblies 22, a bottom pair of movable gripping arms 24, and a bottom arm actuator 26. It can been seen that the bottom wrench assemblies 22 are mounted at an open end of each bottom arm 24 and are shown in contact with a section of the drill pipe 2. Details of the bottom wrench bracket assembly 22 will be described hereinafter in greater detail. The movable arms 24 are mounted by means of pivot mounting pins 15 to a bracket section (not shown) of the support structure assembly 10. The gripping arms 24 may be pivotally connected either jointly with a single pin for both arms. It will be understood that the bottom arms 24 may be connected in the same manner as the top arms, described above.

The bottom arm actuator 26 is pivotably linked to each arm 24 by arm actuator pivot pins 27. The arm actuator 26 allows the gripping arms 24 to be closed or opened around the outer circumference of the pipe section 2, in order for the bottom wrench assembly 20 to engage differing casing sizes. The arm actuator 26 is preferably a hydraulic cylinder of a known type recognized in the field, therefore detailed explanation of such an actuator is unnecessary, although it will be understood other types of linear actuator may be employed.

Referring now to FIGS. 4A and 4B, the top wrench assembly 10 is shown directly mounted on top of the bottom wrench 20 assembly. Due to the top wrench bracket assemblies 12, the top wrench assembly is able to allow relative rotation of the drill pipe section 2 therewith, enabling a drill string making operation. Due to the bottom wrench bracket assemblies 22, relative rotation of the drill pipe section is not allowed therewith, enabling a drill string breaking operation.

The top wrench bracket assembly 12 is shown in greater detail in FIGS. 5A and 5B. Each top wrench bracket assembly 12 includes a bracket 52 which carries a die holder 53, a die insert 54 in a slot (not shown) in the die holder 53, at least two rotatable rollers 55, motors 56 for driving the rotatable rollers 55, and an actuator 57 such as a hydraulic cylinder, for the die insert 54 to provide the wrenching action of the die insert 54 within the slot against the pipe section 2. Such die actuators used in such particular applications are known in the art and therefore further explanation thereof is unnecessary. The top wrenching assemblies 12 are mounted to the top arms 14 by means of a pivot connection 58. The pivot connection 58 allows for the bracket 52 to pivot relative to the pipe section 2 to allow for the rotatable rollers 55 to easily engage the circumference of the pipe section 2.

The bottom wrench bracket assembly 22 is shown in greater detail in FIG. 6. Each bottom wrench bracket assembly 22 includes a bracket 62 which carries a die holder 63, a die insert 64 in a slot (not shown) in the die holder 63, at least two fixed rollers 65, and an actuator 67 such as a hydraulic cylinder, for the die insert 64 to provide the wrenching action of the die insert 64 within the slot against the pipe section 2. Such die actuators used in such particular applications are known in the art and therefore further explanation thereof is unnecessary. The bottom wrenching assemblies 22 are mounted to the bottom arms 24 by means of a pivot connection 68. The pivot connection 68 allows for the bracket 62 to pivot relative to the pipe section 2 to allow for the fixed rollers 55 to easily grip the circumference of the pipe section 2.

The assembled apparatus as seen in FIG. 1, includes a camming mechanism 50 attached to the support structure 30. A cam 72 having an arcuate path is attached to a top portion of the support structure 30. A cam follower 74 is engaged in the cam 72 and is supported relative to the cam 72 by means of a cam follower bracket 75. The top wrench camming actuator 18 is attached to the cam follower bracket 75, and as will be understood by those familiar in the art, through a series of linkages 76 connected to the cam follower bracket 75, and by the connection of the top wrench camming actuator to the top wrench assembly 10, the entire top wrench assembly 10 may be cammed or rotated relative to the centerline of the pipe section 2. The top wrench bracket assemblies 12 as described herein previously, allow for the relative rotation of the rotatable rollers 55 on the surface of the pipe section 2. While the top wrench assembly 12 is being cammed about the pipe section 2, the die insert actuators 57 move the die insert within the brackets 52 to engage the surface of the pipe section, thereby forming or making the drill pipe string.

The top wrench assembly 10 sits on the bottom wrench assembly 20 and can be rotated freely about the center of the string 2 by the actuator 18 which is attached to the back end of the top wrench assembly 10 at one side thereof and to the support structure 30 on the end 32 thereof. The cam 72 and the cam follower 74 guide the rotation and provide additional support for the top wrench assembly rotation on top of the bottom wrench assembly. The top wrench assembly 10 is also guided by a cam follower which may be embodied as in the preferred embodiment by a pair 74 of cam followers mounted on the top wrench 10 and engaged with the cam 72. The cam 72 attached to the support frame has the same diametric center as the pipe section or string 2 so that once the top wrench assembly 10 rotates thereabout the cam follower 74 rotate about the center of the string within the cam 72.

It will be understood that the control device 40 provided is capable of controlling all of the motors, actuators, etc., associated with the apparatus 1 described herein.

The foregoing relates to the preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. 

1. An apparatus for making or breaking a tubular drill string, having a wrenching mechanism integrated with a rotating mechanism, comprising: a first wrench assembly (10) including a first bracket means (12) for carrying a die insert (54); actuating means (57) for actuating the die insert (54) within the first bracket means (12) to position the die insert relative to a pipe section (2) during a drill string making process; and a pair of rotatably driven rollers (55) mounted rotatably on the first bracket means (12), wherein the die insert (54) is disposed on the bracket means (12) at a symmetrical center between the pair of rotatably driven rollers (55).
 2. The apparatus according to claim 1, wherein the first wrench assembly (10) further includes a pair of movable gripping arms (14) pivotally connected together, wherein a first bracket means (12) is pivotably mounted to each of the movable gripping arms (14).
 3. The apparatus according to claim 2, further comprising a camming means (18, 50) for rotating the first wrench assembly (10) relative to a support member around a centerline of a pipe section 2 during a drill string making process.
 4. The apparatus according to claim 1, further comprising a second wrench assembly (20) including a second bracket means (22) for carrying a die insert (64); actuating means (67) for actuating the die insert (64) within the second bracket means (22) to position the die insert relative to a pipe section (2) during a drill string breaking process; and a pair of rotatably fixed rollers (65) fixedly mounted on the second bracket means (22), wherein the die insert (64) is disposed on the second bracket means (22) at a symmetrical center between the pair of rotatably fixed rollers (55).
 5. The apparatus according to claim 4, wherein the second wrench assembly (20) further includes a pair of movable gripping arms (24) pivotally connected together, wherein a second bracket means (22) is pivotably mounted to each of the movable gripping arms (24) of the second wrench assembly (20).
 6. The apparatus according to claim 6, wherein the second wrench assembly (20) embodies the support member. 